We survey and organize over fifty years of theoretical research on status and expectation state processes. After defining some key terms in this theoretical approach, we briefly describe theories and branches in the program.

We also focus on a few theories that illustrate distinct patterns of theory growth, using them to show the variety of ways in which the research program has grown.

The program structure developed from a single set of theories on development and maintenance of group inequality in the 1960s to six interrelated branches by 1988. Between 1988 and today, the overall structure has grown to total 19 different branches. We briefly describe each branch, identifying over 200 resources for the further study of these branches.

Although the various branches share key concepts and processes, they have been developed by different researchers, in a variety of settings from laboratories to schools to business organizations. Second, we outline some important issues for further research in some of the branches. Third, we emphasize the value of developing new research methods for testing and applying the theories.

These theories have been used to explain phenomena of gender, racial, and ethnic inequality among others, and for understanding some cases of personality attributions, deviance and control processes, and application of double standards in hiring.

Status and expectation state processes often operate to produce invidious social inequalities. Understanding these processes can enable social scientists to devise more effective interventions to reduce these inequalities.

Status and expectation state processes occupy a significant segment of research into group processes. This chapter provides an authoritative overview of ideas in the program, what is known, and what remains to be discovered.